The conventional method of making a prototype automobile body is to first sculpt the body in modeler's clay. Skilled industrial sculptors transform body prints, drawings of a concept vehicle and/or verbal directions into a full-size three dimensional model. Modeling clay has long been used for its ability to be worked and reworked until the desired design is achieved. However, the ability to rework the styling clay also permits substantial variations from the initial concept to be incorporated in the final model. While a clay model may be studied to get a general idea of the design, it is still necessary to visualize the final appearance of the car without paint or trim.
Due to the large investment required in developing a new automotive or other product design, it is preferable to be able to evaluate a new design as it will finally appear, complete with realistically appearing paint and trim. When a clay styling model is made it can not be painted or trimmmed but is used as a pattern for a plaster or plastic cast mold. After a mold of the clay model is formed, fiberglass is then cast in the mold to the shape of the original clay model. The fiberglass body is then removed from the mold and finished by painting and assembling final trim and glass to permit evaluation of the product in its final form. The above process typically takes from three to four months and is extremely costly. If the final model is not satisfactory it may be necessary to push back production plans to permit the preparation of another clay model and fiberglass casting.
An example of a sports car body fabricating method is disclosed in an article entitled "Centaur", Road & Track Magazine, May 1963, pages 70-2. The Centaur body is made of glass fiber reinforced plastic that was molded from a mockup pattern made of polystyrene foam blocks fitted between plywood bulkheads. The mock up pattern is sculpted in polystyrene foam which is covered with a hard surfacer before making a mold for the polystyrene foam body.
Another alternative to the conventional clay modeling method is known as the epowood process wherein plywood panels are attached to a welded steel frame. According to the epowood process a plywood armature is assembled to precise specifications on a surface plate. Polystyrene foam blocks are then bonded to the armature and are covered with a thick layer of an epoxy resin base material. The epoxy resin base material is shaped to a rough body contour and then marked with horizontal body lines which are transferred from the drawing by placing a plan view template on the surface plate and tracing the outline of the template with a vertical angle block having a router attached thereto at a height corresponding to the horizontal body line of the plan view section to form a groove in the epoxy resin material. Making templates and grooving the epoxy resin material is repeated at vertically spaced intervals. After all of the grooves have been formed in the epowood material an industrial sculptor carves the remaining epoxy resin material to form a contoured surface interconnecting the grooves. The model may then be painted with a polyurethane paint and fitted with trim pieces as appropriate to complete the model.
Both of the processes outlined above are laborious procedures. The Centaur process requires making a mold of the covered polystyrene foam mock up pattern and formation of a fiberglass body. The epowood process requires preparation of complete body line drawings and templates as well as the use of an expensive surface plate for accuracy. In both methods the skills of an industrial sculptor are required in many phases of the procedure.
The above problems and other have been solved according to the method of the present invention.